Axiom Home Page Forums General Discussion Home Theater MP3 vs Lossless Compression - the proof

If there's one thing I know, it's my digital audio theory.

After seeing Digitize Design Group's (a Finnish C64 "demo" group) demo - Sabrina "Boys, Boys, Boys" (available for the C64 emulator users here) in 1989, I HAD to learn about this way to get real music to play on my computer... none of this SID chip FM-synthesized stuff.

Long story short - I built a digitizer and started messing around with compression (48K isn't a lot to work with), mixing and sequencing.

Then came the Sound Blaster (8 bit mono? Beats 4 bit mono!) and the PC and it was a whole new ballgame.

Bren R.

Ok, this is going to sound like a plug here, and I guess that it is since I know the guy, but what the heck. A few folks in the thread have mentioned that they're intimidated by trying to rip all their CD's themselves. I admit that it's not difficult to do this for a few CD's but when you have a bunch, the process can get a little daunting. Anyway, a friend of mine is in the process of starting a business where for a few bucks he'll rip your CD's for you in most any format you'd like and then burn them to one or more DVDs for you. I was planning on having him rip my 200 or so CD's and then just copy the DVD(s) to my hard drive. Then I'd proceed with the listening to the ripped songs using the previously mention SqeezeBox or AudioTron. He hasn't actually performed this service for any paying customers yet, but I'm sure he'd appreciate any feedback any of you had on his concept. You can check out his site at FreeYourCDs.

The free alternative, of course, is to do it yourself over time. Most ripping programs I am aware of will automatically contact the CDDB and get the album information for each CD, saving you from having to manually enter any data. They can also be set to auto-rip mode so all you have to do is drop in a CD. It'll rip it and then eject it so you can drop in the next CD. Keep going until you get sick of it.

You can burn your entire library piecemeal in less time than you think.

Hi pmbuko,

Yes, I whole heartedly agree with you. The cheapest way of doing this is to do it yourself. You can do it for free and can get the results you want that way. But it will take time - if you have the time that's fine.

The service I'm in the process of starting up (apologies for the still lame web site: www.fycd.com) is all about convenience. I first got interested in the idea when after three years of having an MP3 player I still found that:
(a) I didn't have my enitre collection copied (I only had about 25% done - which represented my current favorites)
(b) I had a variety of formats and still hadn't decided what was best (the answer is, of course, one size doesn't fit all!)

I searched for the idea of a "bulk encoding service" but couldn't find anything at the time. So I plunked down a couple of grand on some equipment and got busy designing, coding and modifying. While doing this I've since found about half a dozen competitors (but I think I'm better than them - of course you need to decide for yourself).

What makes the FYCD service unique is the widest range of encoding / compression choices and also a unique "DIY" option. With the "DIY" option we supply you with your CDs copied to WAVs and some software (just Windows at this point - but I'll tackle others later) to allow bulk encoding/compression to your choice. This approach allows you to (a) encode to different formats as your needs change (b) re-encode in the future when a new encoder or compressor hits the streets.

This is still very much in "beta mode" but I'd love to hear from any and all on whether this is a great idea or a lousy idea.

Many thanks if you took the time to read this. Sorry if I'm breaking ettiquette by posting a plug - but if you help me out then I'll try and help you out with the FYCD service

I didn't mean to knock your service. I'm sure it would be worth a lot of people's time to take care of it all at once. I just wanted to make sure people were aware of the DIY route.

Hey, just popping in for a bit.

Bren, interesting thread. However, I'm not sure of the methodology in your experiment- hear me out.

***Warning: somewhat technical***

MP3, like all modern compressed audio formats, relies on the imperfections of the human ear, significantly in the phenomenon of 'masking'. That is, a tone of a certain frequency may 'mask' weaker tones around it. Think of an MP3 encoder calculating a spectrum graph every 1/75 of a second, finding the spectrum peaks, and marking all nearby weaker tones as 'masked' (the ear ignores these in the presence of the strong tone). The MP3 codec throws these masked tones out.

Fast forward to doing a waveform difference on compressed vs uncompressed audio: part of the difference will be these 'completely masked' tones, but as the dominant, masking tone is gone (since it's the same), you'll hear these otherwise-invisible sounds.

Likewise, if the psychoacoustic model MP3 uses is wrong for your ears, just a little difference in the waveform may unmask borderline tones or mask otherwise-audible tones.

So, neither of the two 'obvious' conditions hold: either that a small difference in waveforms strongly implies that the two waveforms will sound the same to a given person, or that a big difference in waveforms strongly implies that the two waveforms will sound different to a given person.

Counter-intuitive, I know. Blame our ears.

RD

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Fast forward to doing a waveform difference on compressed vs uncompressed audio: part of the difference will be these 'completely masked' tones, but as the dominant, masking tone is gone (since it's the same), you'll hear these otherwise-invisible sounds.

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Exactly - part of the MP3 compression scheme they claim is that if a triangle is being struck at the same time as a bass drum, you'll never hear the triangle - but how does a computerized encoder know what's a triangle and what's a bass drum? I'm assuming that if there's a loud sound in a certain frequency band, that it ignores or uses less resolution in the other frequencies. It's hard to say. In the end, I was just showing what the differences were between the two. People can make their own decisions.

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Likewise, if the psychoacoustic model MP3 uses is wrong for your ears, just a little difference in the waveform may unmask borderline tones or mask otherwise-audible tones.

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You speak of the Golden-Earred?

Bren R.

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You speak of the Golden-Earred?

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Didn't they do "Radar Love" or some other 70's arena rock anthem?

Hey, if CDex calls the LAME encoder, what's the difference between using that and using EAC? Is that a stupid question?

Also, Neverhappy really likes the 320 bit coding, and the quality-preservationist in me buys that premise. Is there ANY advantage (besides saving some disk space) of using variable bit rate instead? Is there a circumstance in which VBR could be better than 320? Why don't some people like using VBR?

Thanks for suffering my questions.

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Is there ANY advantage (besides saving some disk space) of using variable bit rate instead?

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Other then space, I can think of none.

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Is there a circumstance in which VBR could be better than 320?

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See above! The main reason I don't like VBR is simple. It's yet one more thing your letting the codec decide. How can it know what you want left in and what you want taken out? So I keep it at 320 and take it out of the equation.

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Why don't some people like using VBR?

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The question should be, why do some people use it? lol Just kidding on that one!

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Hey, if CDex calls the LAME encoder, what's the difference between using that and using EAC? Is that a stupid question?

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All ripping software is not the same and I will leave it at that. The way they look for errors to the way they actually handle errors is very different from software to software.